Urinary incontinence is the unintentional passing of urine. It is a very common problem and is thought to affect more than 50 million people in the developed world.
How the bladder works
The bladder is a stretchy, muscular bag that collects and stores urine. It is located in the pelvis at the lowest point in the abdomen, immediately behind the pubic bone.
The bladder receives urine from the kidneys, which filter waste products from the blood and mix them with water to create urine. This is passed down to the bladder through tubes called ureters.
Urine is stored in the bladder, which is supported in the pelvis by pelvic floor muscles. Some of this muscle wraps around the urethra, the tube that runs from the bladder to outside the body, to help keep it closed until you need to pass urine.
Once the bladder is full, a signal is sent to the brain that you need to pass urine. When you are ready, the brain tells the pelvic floor muscles to relax and open the urethra. The muscles around the bladder contract and push the urine out.
A problem in any part of this process can result in urinary incontinence.
Types of urinary incontinence
There are several types of urinary incontinence, but the most common are:
- stress incontinence, when the pelvic floor muscles are too weak to prevent urination, causing urine to leak when your bladder is under pressure, for example when you cough or laugh
- urge incontinence, when urine leaks at the same time or just after you feel an intense urge to pass urine
These two types of urinary incontinence are thought to be responsible for over 9 out of 10 cases. It is also possible to have a mixture of both stress and urge urinary incontinence.
How common is urinary incontinence?
It is not clear exactly how many people have urinary incontinence, possibly because urinary incontinence can be defined in different ways. Some people may also not report their condition because of embarrassment.
Figures from a study that included the UK found that 13% of women and 5% of men had some degree of urinary incontinence. In general, urinary incontinence affects twice as many women as men and becomes more common with increasing age.
There are several known risk factors for urinary incontinence, such as childbirth in women. See Urinary incontinence - causes for more information about this and other causes.
Outlook
Urinary incontinence can be an uncomfortable and upsetting problem. Many people think that it is an inevitable part of ageing, but there are several forms of effective treatment, including:
- lifestyle changes, such as losing weight
- pelvic floor muscle training (exercising your pelvic floor muscles by squeezing them)
- bladder training, so you can wait longer between needing to urinate and passing urine
Studies from around the world suggest that conservative treatments, such as those above, can improve stress or mixed urinary incontinence in women by two-thirds.
If these treatments are not effective, several medications may be tried, and a growing number of different surgical techniques offer long-term results. See Urinary incontinence - treatment for more information about the different treatment options.
Abdomen
The abdomen is the part of the body between the chest and the hips.
Bladder
The bladder is a small organ near the pelvis that holds urine until it is ready to be passed from the body.
Kidneys
Kidneys are a pair of bean-shaped organs located at the back of the abdomen. They remove waste and extra fluid from the blood and pass them out of the body as urine.
Pelvic floor muscles
The pelvic floor muscles support and hold in place your bladder and urethra. They give you control over your bladder and are used to urinate.
Urethra
The urethra is a tube that carries urine from the bladder to the outside of the body.
